The invention discloses a method for improving an ash storage field of a
coal-fired power
plant by utilizing stepped mixed planting of leguminous plants. The method comprises the following steps: partitioning the ash storage field of the power
plant planned to be improved and leveling the field; the field is divided into a first step area, a second step area and a third step area according to soil severity reduction in sequence, steps are constructed and excavated to form a platform, a planting area is created,
irrigation and drainage facilities are arranged, and soil improvement is carried out; planting
medicago sativa in the planting area of the first step area; ditching, ridging and planting
robinia pseudoacacia in the planting area of the second step area; planting
albizia julibrissin seedlings in the planting area of the third step area; and performing field management and
pest control on alfalfa,
robinia pseudoacacia and
albizia julibrissin seedlings. The land surface can be quickly covered, raised dust is radically treated, the leguminous plants fix
nitrogen and increase
fertility, soil is remarkably improved, and water and
soil loss is prevented through the root systems of the leguminous plants; leguminous plants and shrubs are mixed and planted to gradually form an ecological
system, so that the biological diversity is improved.